Automobile-tire.



L. HOFIVIEISTERV AUTOMOBlLE TIRE. APPLlcAUoN man MAH. 19. mi.

Patented Aug'. 1918.

'MN5/WUR admitted to "the LEO HOFMEISTER, 0F MILWAUKEE, WISCONSIN.

AUTOMOBILE-TIRE.

To all wlmi/i t may concern.'

Be it known that I, Liao IIorzurLis'rI-m, a citizen of the United States, and resident of Milwaukee, in the county of Milwaukee and State of lVisconsin, have invented new anduseful Improvements in Automobile-'l`ires, of which the followingI is a description, reference beingr had to the ace-empanying"- dra nings, which are a part. of this speriliration.

The invention relates to pncmnatie tires and has for its object to proride a consu-uction whereby its liability to puuclure will 'be reduced to a minimum.

The invention is furtherdesigned to provide an automobile tire haring an outer rasing, an inner self-sustaining pneumatic tiro and a layer or intermediate massl of sponge rubber composition of considerable depth interposed between the outer easing and the inner tire.

The invention further onsists in the several features hereinafter set forth and more particularly defined by claims at the conclusion hereof.

In the drawings:

Figure 1 is a vertical sectional View of a portion of the tire embodying the invention;

i 2 is a section taken on the line 2-: of F 1g. 1.

1n general the tire consista of an outer cas ing 3, an inner self-sustaining pneumatic tire Ll, and an intermediate layer of sponge rubber or other yielding omlfosition 5 disposed between the outer casing 3 and the tire 4.

The outer casing 3 may be of any def sired construction and is preferably of the elencher type in which the circumferential edges 6 are hooked under or held by the curved anges of the riin 7 so that when the tire is inflated the outer easing will be firmly held in place upon the rim and so that on the deflation of the tire said casing may be readily detached from the'rim. The outer casing 3 is provided with the usual inside fabric flap il to protectthe inner tire from therim The inner pneumatic tire 4 consists of a self-sustaining rubber tube. By the term self-sustaining tube, I mean a tube of limited expansibility so that when Said tube s inflated it will sustain the air pressure Within it andwill not depend for the limiting of its expansibilit upon the outer easing .as is the case with t e 'ilai inner tube. Air is tire or @single-'through `'a Specification of Letters Patent. Application tiled March 19, 1917.

termediate com Patented Aug'. 6, 1918. Serial No. 165,789.

valve l of usual construction. The self- ,sustaining tire may be of an internal di nef ter such as is commonly used in bicycles and motorcycles .so as to provide a space of considerable distance between the top of Said rtire fl and the top ol the outer casing 3. 4

The intermediate layer of yielding material 5 is preferably a spongy rubber compolsition which is interposed betwcenihc outer casing 3 and the tire` i to substantially iill the spare therelwtwecn, the lower portion S of said composition being,lA curved to i'onforni to the curve of the tire -l and there bein;- an oir spree 9 left between the outer and inner tires adjacent the rim 7.

W'ith the construction of tire shown and described when the inner tire l is infiated as shown in Fig. 2 it will press upwardly against the spoil 'y intermediate portion 5 which in turn willgexert pressure against the outer easing 3 to maintain it in expanded position and hold it on the rim and it will be very diicult, in fact almost impossible, for any sharp element, such as nails or tacks, to pierce the inner tire 4 because of the considerable depth of the spongy7 intermediate portion 5 through which said elelnent'would lave to pass to puncture the pneumatlc tire. Furthermore the formation of the air space 9 between the inner and outer tires relieves the sides of the outer casingr of the usual side pressure of the inner tube against it so as to prevent.blowouts from the side or rim of the easing. the lower portion 10 of the spongy coinposition serving to maintain this intern'iediate air space 9 between the two tires. Furthermore the tube l when inflated does not expand laterally into the airspace as will be apparent from Fi .2 and consequently the tube 4 is protectet on its sides and the outer casing is also relieved ofthe side pressure which would occur were said tube 4 expanded laterally against the sides of the outer casing.

It will also be noted when the tire is in- Hated and meets with an obstruction tending to ila-tten the tread, the outer casing will be free to stretch laterally because ofthe local com ressibility of the s on e rubber and that t ie inner tire will-be itt eal'ected if at all because the force striking the tire is taken up bythe outer casing and the inosition. i The cushion ispreerabl attached tothe tire 4 but may be removably d the tires but in either ease it is held outisposed between 'nel' easing is ln' the inllntetl wstr'tlly :igninnt the untel' tire the inner tire withnnt sith piesnin'e nent Vini ptn'Linn of the untel-'tire'.

Whnt l ehiini ns my inventinn is:

l. ln n tire. the i-nntliinntiun nl nn untel' easing. at Apartite lwlf-snstninin i' pnennnite inner tuning nl lilnitetl e\'|i:tn.\i iility. :intl n lnyel nf wielding." nnitel'inl ititetlmsetl it tween snit inner :Intl unter enhingls to fnrln n enshiun therein-tween of etnnshlei'nhle depth lnlt nnl pin-tinllv lilliny,"l the 51mm between Sztiil ensings tti fui-ni nii' spnees between satitl enninprh :nljnt'ent the linih 2. ln n tirtn nt nn ontw tnhnhn tnlnlhu' tlinnietei' thnn the inteit-:ising tu spnee Snitl innei' etw-ing' l'tnni tlnsith-h nntl trend pnttinn nf the unter easing '.tlmve the vim` mul n in wi nf sponge emnpositinn intei'lmsetl between said inner nml ontei" Casing hin nnly partially tilting the'spnee between lnhl eus-ing to {tw-m nin-spines between the enh-ings ntljneent the vini when ywahl inner mixing is inntetl.

il. ln n tire. the .emnliinntion` with n t'iln. nl :in unter mining;tletnehnhly seein-eil to snitl rim` :t seltsnstnining pnennnitic inner casingwif liinitell expniisihility tlisponetl within the unter t-mnng mljneent snitl i'nn itnd being nl' |miller tlhnnetel' than the. tintelensing Sn :is tu he within it nml `be spnct'tl from the ities :intl top nt' the intel-ini' 0l' the unter ensin; I when inllntetl` nntl n hiyel of `Yieltling nintei'izil disposed between the trend portion nl' the inter t-tising und that nf the inner easing. lmiti innetmsinp; serving tn hol Ititl unter easing in tension without exerting ith pressure ngrninst the l'itles; nf snitl unter engin;h :nljneent the riin.

ln te'in'tnny whereof I LEO 1-1( FMElSTElt.

nllix my rwignntnre. 

